Cabletron Systems MMAC-Plus 9G426-02, User Manual

Page: 31 / 44

3-3
Operation
A VLAN is a local area network of endpoints having full connectivity (sharing
broadcast, multicast, and unicast packets) independent of any particular physical
or geographical location. In other words, endpoints that share a virtual LAN
appear to be on a single LAN segment regardless of their actual location. Changes
to VLANs (e.g., moving nodes) are accomplished via software , which reduces
network management time and expense.
VLANs extend direct communication between users beyond the constraints of a
physical LAN segment by allowing the establishment of VLANs that encompass
users on multiple physical LAN segments. This permits endpoints to be
administratively grouped. For example, in Figure 3-2, the users on LANs A and B
belong to the Finance group, however, they are physically removed from each
other and as such cannot communicate directly. The VLAN solution places both
LAN segments on the same VLAN; all endpoints appear and act as if they are on
the same physical LAN.
Most VLAN implementations require a router for Inter-VLAN communication;
Cabletron’s SecureFast VLAN operational model does not. Inter-VLAN
communication is accomplished via multi-layer switches or optional traditional
router.
Figure 3-2. VLAN-based Network
Endpoints on VLAN 1
Endpoints on VLAN 2
SFS Network
LAN A
LAN B